Is 14,000 BTU a big size air conditioner for a 320 square foot room?

Question

In the summer, I use a 14,000 BTU air conditioner to cool down my room. However, it does not cool my place the way I want it to. The room of the ac will cool to 70 degrees or sometimes not cool below 74 on a really hot and humid day (90 degrees and higher with 40% humidity or higher) while the back of the room on average is 3 degrees warmer. So the main room will cool to 70, the back of the main room cools to 73, the nearby bedroom holds steady at 76-77 while the back of my apartment stays at 79-80 degrees. My apartment is 2 bedrooms and 1 bathroom so the apartment is about 740 square feet in total. The kitchen easily heats it up by 2-4 degrees in the summer so I'm sure the kitchen is a major heat load other than the warm outdoor temperatures. I'm not so sure about the insulation but I am guessing that the insulation is not the best since the building was completed in the 1890s. So I use one main air conditioner to cool the entire apartment. It is a portable air conditioner rated at 14,000 BTUs and uses 1250 Watts. The problem is that the master bedroom can be too chilly, the other bedroom is a bit warm but not as cool, and then the hallway is pretty much heated from the kitchen and so is the bathroom a bit. So there is no uniform temperature throughout the apartment. It ranges from too cool to too warm. Adding a 2nd air conditioner would certainly help but that would trip the circuit if I run 2 air conditioners at the same time. Maybe I should get another air conditioner?

Mr. Interesting · Answer

Yes. That will cool that much space quite well IF the unit is working correctly.  https://www.google.com/search?q=how+many+btus+to+cool+room&rlz=1C1CHBF_enUS711US711&oq=how+many+btus+to+cool+room&aqs=chrome..69i57j0i22i30l4.11346j0j15&sourceid=chrome&ie=UTF-8

y · Answer

If I understand, you are using one portable unit to cool an entire apartment from, a single location. 
Insulation, windows, doors, construction all go to sizing.  Even up here in Ma where I am, 14000 btu unit would be stretching for 750 sq ft.  Your issues, is air flow. Moving the conditioned air to the farthest places and moving the warm back, to be treated.  You'll need fans, maybe even some sort of portable duct work to make that happen. Or, multiple smaller units spread around.

Anonymous · Answer

The problem is walls. Walls are very good stoppers of air circulation, even with open doors.  Now, what you need are fans, in particular ceil fans in each room (if you have high enough ceilings), to stir the air.  If ceiling fans won't work, then some some cheap, small fans placed in key areas to push the cool area.  The 14,000 BTU A/C should be big enough, but double check the recommendations for size.  The heat is related more to an insulation problem.  You need more insulation in the attic and shade on your windows.  Check to see if you can put the 2nd  A/C on a 2nd circuit.

Spock (rhp) · Answer

there should be a separate circuit in the kitchen; using it should solve the two units overload issue.  sadly, you've told us little about your climate or exposure to the summer sun.  those, along with insulation, determine how hard the a/c has to work.  ask your landlord.  with good insulation [and as long as you're not in Vegas or someplace in the desert], 14,000 BTU should be enough for a 550 sq ft space -- maybe just enough for your space.  Your experience suggests that it isn't quite enough for your taste -- so a second a/c is the way to go.  [personally, i'm in south florida and have my a/c set to 78 in the summer -- but then, by contrast to outside where it can be 93 with 80+ percent humidity, that's wonderful] -- grampa

Is 14,000 BTU a big size air conditioner for a 320 square foot room?

4 Answers